BibSlavKon: 36 hits for Proto-Slavonic Seen as a Hypothetical System, the Directions of its Evolution in Individual Slavonic Languages (with Special Reference to Closely Related Languages) on page 3

The Bibliography of International Congresses of Slavists (1929-2018) was converted from thirteen printed volumes into a database in cooperation with the Slavonic Library in Prague (Slovanská knihovna Praha) and contains 8550 records. Since 2008 the Bibliography appear only in electronic form and will be updated in five-year interval according to the next Congresses of Slavists. The further information can be found here. The overview of the classification can be found: here.

Your search for Proto-Slavonic Seen as a Hypothetical System, the Directions of its Evolution in Individual Slavonic Languages (with Special Reference to Closely Related Languages) provides 36 hits
21	K voprosu o suščestviteľnych s osnovoj na -j : ich roľ i kontaminacija s osnovami na -ǒ v Marlinskom četverojevangelii Lieli, P. - Studia Slavica Academiae scientiarum Hungaricae 19 (1973) 1/3, 197-205
22	Das Götterdvandva im Slavischen : Versuch einer Erklärung des sog. Genitiv-Akkusative Liukkonen, K. - Scando-Slavica (1973), 249-253
23	Das slavische Kasussystem : (Prof. Dr. B. Havránek zum 80. Geburstag gewidmet) Mareš, F. V. - Wiener slavistisches Jahrbuch : Beiträge österreichischer Slavisten zum VII. Internationalen Slavistenkongress Warschau 1973 (1973), 56-95
24	Die verbalen Nasalsuffixe im morphologischen System des Urslavischen Mathiassen, T. - Scando-Slavica (1973), 245-247
25	The Common Slavic Verbal System Micklesen, L. R. - American Contributions to the Seventh International Congress of Slavists : Warsaw, August 21-27, 1973 (1973), 241-273
26	Rozwój systemu fonologicznego od wspólnoty językowej prasłowiańskiej do języka Cyrila i Metodego Moszyński, L. - Z polskich studiów slawistycznych. Seria 4, Językoznawstwo (1972), 293-304
27	Der Dravänopolabische Wortakzent. Teil I Olesch, R. - Slavistische Studien zum VII. Internationalen Slavistenkongress in Warschau 1973 (1973), 389-418
28	Nove smernice u proučavanju istorije slovenskih jezika : fakta kao efekti procesa i uzroci procesa i fakata Pavlović, M. - Referati za VII međunarodni kongres slavista u Varšavi (1973), 1-10
29	Vliv latinské skladby na staropolskou syntax Petr, J. - Československé přednášky pro VII. mezinárodní sjezd slavistů ve Varšavě (1973), 67-74
30	Verbale Rektionskomposita mit regierendem Vorderglied im Slavischen und in anderen indogermanischen Sprachen Pohl, H. D. - Wiener slavistisches Jahrbuch : Beiträge österreichischer Slavisten zum VII. Internationalen Slavistenkongress Warschau 1973 (1973), 190-202

Bibliography of International Congresses of Slavists (BibSlavKon)